Flame retardant aromatic polycarbonate resin composition

ABSTRACT

An aromatic polycarbonate resin composition having: 100 parts by weight of a resin component (A) mainly having an aromatic polycarbonate, 0.1 to 200 parts by weight of a solid inorganic compound (B), at least one compound (C) selected from the group consisting of an organic acid, an organic acid ester, and an organic acid anhydride, 0.001 to 1 part by weight of at least one organic acid metal salt (D) selected from the group consisting of an organic acid alkali metal salt and an organic acid alkaline earth metal salt, and 0.01 to 1 part by weight of a fluoropolymer (E), wherein compound (C) is present in an amount wherein a mixture of compounds (B) and (C) exhibits a pH value of from 4 to 8.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a flame retardant aromaticpolycarbonate resin composition. More particularly, the presentinvention is concerned with an aromatic polycarbonate resin compositioncomprising: a resin component (A) mainly comprising an aromaticpolycarbonate, a solid inorganic compound (B), at least one compound (C)selected from the group consisting of an organic acid, an organic acidester; and an organic acid anhydride, at least one organic acid metalsalt (D) selected from the group consisting of an organic acid alkalimetal salt and an organic acid alkaline earth metal salt, and afluoropolymer (E), wherein the compound (C) is present in an amountwherein a mixture of the inorganic compound (B) and the compound (C)exhibits a pH value of from 4 to 8. The aromatic polycarbonate resincomposition of the present invention is advantageous not only in that itexhibits an excellent flame retardancy without using a bromine compoundor a phosphorus compound as a flame retardant (especially when a verythin shaped article is produced using the aromatic polycarbonate resincomposition of the present invention, the produced very thin shapedarticle exhibits an extremely high level of flame retardancy as comparedto the case where a conventional aromatic polycarbonate resincomposition is used), but also in that it exhibits excellent propertieswith respect to melt stability, thermal aging resistance, resistance tomoist heat, stiffness and impact resistance. Therefore, the aromaticpolycarbonate resin composition of the present invention can beadvantageously used for producing various shaped articles, such as aninjection-molded article, and an extrusion-molded article.

2. Prior Art

An aromatic polycarbonate is a resin which not only has excellentmechanical properties (e.g., impact resistance) but also has excellentheat resistance. Therefore, an aromatic polycarbonate has been widelyused as materials for housings or parts of various computers (e.g., adesktop computer and a notebook computer), printers, word processors,copying machines and the like.

In recent years, with respect to a shaped article obtained from anaromatic polycarbonate, especially in the case where it is intended touse the shaped article as a housing, it has been strongly desired toreduce the thickness of the shaped article so as to reduce the weightthereof. However, a thin housing is likely to suffer distortion byexternal stress or under the load of the parts inside the housing.Therefore, there has been a strong demand for aromatic polycarbonateshaving high stiffness and high dimensional precision.

In an attempt to improve the stiffness and dimensional precision of anaromatic polycarbonate, a method has been proposed in which an inorganiccompound, such as a glass fiber, a carbon fiber, talc, mica orwollastonite, is blended with an aromatic polycarbonate as a reinforcingagent and/or a filler.

However, an aromatic polycarbonate resin composition containing aninorganic compound poses a problem that, during the molding of the resincomposition, the inorganic compound promotes the decomposition of thearomatic polycarbonate. Especially the use of a basic inorganiccompound, such as talc or mica, in an aromatic polycarbonate resincomposition poses a problem that the melt stability of the resincomposition is markedly lowered, so that the properties of the resincomposition are markedly impaired during the molding thereof.

For solving the above-mentioned problems, various proposals have beenmade for suppressing the lowering of the molecular weight of an aromaticpolycarbonate (i.e., for suppressing the decomposition of an aromaticpolycarbonate). For example, Unexamined Japanese Patent ApplicationLaid-Open Specification No. Hei 2-283760 proposes the addition of aphosphorus compound; Unexamined Japanese Patent Application Laid-OpenSpecification No. Hei 3-21664 proposes the addition of an organic acid;and Unexamined Japanese Patent Application Laid-Open Specification No.Hei 10-60248 proposes the addition of a sulfonic acid phosphonium salt.However, even by these proposals, the melt stability of the resincomposition, especially at high temperatures, was still unsatisfactory,so that the molding temperature of the resin composition is inevitablylimited, that is, only a relatively low molding temperature can beemployed.

On the other hand, with respect to aromatic polycarbonate resincompositions used for office automation machines, and electric andelectronic appliances, it has been desired to achieve excellent flameretardancy as well as excellent stiffness and dimensional precision.Further, in recent years, from the viewpoint of environmentalprotection, it has been desired to develop a flame retardant aromaticpolycarbonate resin composition which contains neither a brominecompound nor a phosphorus compound as a flame retardant.

For example, Unexamined Japanese Patent Application Laid-OpenSpecification No. 2002-80709 describes an aromatic polycarbonate resincomposition which is obtained by blending an aromatic polycarbonate withan inorganic filler, an organophosphorus flame retardant and an alkalimetal salt of an organic acid. This patent document describes that theflame retardancy of the obtained resin composition is “V-0” as measuredin accordance with UL-94 standard with respect to a test specimen havinga thickness of 0.8 mm. However, the resin composition described in thispatent document is disadvantageous in that a phosphorus compound is usedas a flame retardant, and that the properties of the resin compositionare markedly lowered under high humidity and high temperatureconditions.

Further, Unexamined Japanese Patent Application Laid-Open SpecificationNo. 2002-294063 describes a resin composition which is obtained byblending an aromatic polycarbonate with a metal salt of an organic acid,an alkoxysilane compound, a fluorine-containing polymer, an inorganicfiller, and optionally an organosiloxane compound. This patent documentdescribes that, when the above-mentioned organosiloxane compound(optional component) is used, the flame retardancy of the obtained resincomposition is “V-0” as measured in accordance with UL-94 standard withrespect to a test specimen having a thickness of 0.8 mm. However, sincethe resin composition described in this patent document contains anorganosiloxane compound which has a low heat stability, disadvantagesare caused in that, when the resin composition is molten at hightemperatures, the resin composition is likely to suffer discolorationand the amount of components volatilized from the molten resincomposition increases.

Furthermore, Unexamined Japanese Patent Application Laid-OpenSpecification Nos. 2003-82218 and 2003-268226 describe a resincomposition which is obtained by blending an aromatic polycarbonate witha fluorine-containing resin and a silicate compound. However, the resincomposition described in each of these patent documents isunsatisfactory with respect to flame retardancy and melt stability.

As apparent from the above, in the prior art, it has been impossible toobtain an aromatic polycarbonate resin composition, which contains aninorganic compound, and which not only exhibits a high flame retardancyin the form of a very thin shaped article thereof without using abromine compound or a phosphorus compound as a flame retardant (forexample, “V-0” as measured in accordance with UL-94 standard withrespect to a test specimen having a thickness of 1.2 mm, or “5VB” asmeasured in accordance with according to the UL-94 standard with respectto a test specimen having a thickness of 1.0 mm), but also has excellentmelt stability and mechanical strength. Therefore, it has been desiredto develop such an excellent aromatic polycarbonate resin composition.

SUMMARY OF THE INVENTION

In this situation, the present inventors have made extensive andintensive studies with a view toward solving the above-mentionedproblems accompanying the prior art. As a result, it has surprisinglybeen found that, even without the use of a bromine compound or aphosphorus compound as a flame retardant, an aromatic polycarbonateresin composition having a specific formulation (especially in the formof a thin shaped article) not only has a very high flame retardancy (forexample, “V-0” as measured in accordance with UL-94 standard withrespect to a test specimen having a thickness of 1.2 mm, or “5VB” asmeasured in accordance with UL-94 standard with respect to a testspecimen having a thickness of 1.0 mm) as compared to the conventionalaromatic polycarbonate resin compositions, but also has a greatlyimproved melt stability and excellent properties with respect to thermalaging resistance, resistance to moist heat, stiffness and impactresistance. The above-mentioned aromatic polycarbonate resin compositionhaving a specific formulation comprises a resin component (A) mainlycomprising an aromatic polycarbonate, a solid inorganic compound (B), atleast one compound (C) selected from the group consisting of an organicacid, an organic acid ester; and an organic acid anhydride, at least oneorganic acid metal salt (D) selected from the group consisting of anorganic acid alkali metal salt and an organic acid alkaline earth metalsalt, and a fluoropolymer (E), wherein compound (C) is present in anamount wherein a mixture of inorganic compound (B) and compound (C)exhibits a pH value of from 4 to 8. Based on this novel finding, thepresent invention has been completed.

Accordingly, it is an object of the present invention to provide anaromatic polycarbonate resin composition which not only has high flameretardancy (especially, a thin shaped article produced from the aromaticpolycarbonate resin composition has extremely high flame retardancy ascompared to that of a thin molded article produced from a conventionalaromatic polycarbonate resin composition), but also has excellentproperties with respect to melt stability, thermal aging resistance,resistance to moist heat, stiffness and impact resistance.

The foregoing and other objects, features and advantages of the presentinvention will be apparent from the following detailed description andclaims.

DETAILED DESCRIPTION OF THE INVENTION

According to the present invention, there is provided an aromaticpolycarbonate resin composition comprising:

100 parts by weight of a resin component (A) mainly comprising anaromatic polycarbonate,

0.1 to 200 parts by weight of a solid inorganic compound (B),

at least one compound (C) selected from the group consisting of anorganic acid, an organic acid ester, and an organic acid anhydride,

0.001 to 1 part by weight of at least one organic acid metal salt (D)selected from the group consisting of an organic acid alkali metal saltand an organic acid alkaline earth metal salt, and

0.01 to 1 part by weight of a fluoropolymer (E),

wherein the compound (C) is present in an amount wherein a mixture ofthe inorganic compound (B) and the compound (C) exhibits a pH value offrom 4 to 8.

For easy understanding of the present invention, the essential featuresand various preferred embodiments of the present invention areenumerated below.

-   1. An aromatic polycarbonate resin composition comprising:

100 parts by weight of a resin component (A) mainly comprising anaromatic polycarbonate,

0.1 to 200 parts by weight of a solid inorganic compound (B),

at least one compound (C) selected from the group consisting of anorganic acid, an organic acid ester, and an organic acid anhydride,

0.001 to 1 part by weight of at least one organic acid metal salt (D)selected from the group consisting of an organic acid alkali metal saltand an organic acid alkaline earth metal salt, and

0.01 to 1 part by weight of a fluoropolymer (E),

wherein the compound (C) is present in an amount wherein a mixture ofthe inorganic compound (B) and the compound (C) exhibits a pH value offrom 4 to 8.

-   2. The aromatic polycarbonate resin composition according to item 1    above, wherein the solid inorganic compound (B) is at least one    silicate compound selected from the group consisting of a    plate-shaped silicate compound, a needle-shaped silicate compound    and a fibrous silicate compound.-   3. The aromatic polycarbonate resin composition according to item 2    above, wherein the at least one silicate compound is selected from    the group consisting of talc, mica, a glass flake and a glass fiber.-   4. The aromatic polycarbonate resin composition according to item 3    above, wherein the at least one silicate compound is selected from    the group consisting of talc and mica.-   5. The aromatic polycarbonate resin composition according to any one    of items 1 to 4 above, wherein the compound (C) is selected from the    group consisting of an organic sulfonic acid, an organic sulfonic    acid ester and an organic carboxylic acid.-   6. The aromatic polycarbonate resin composition according to any one    of items 1 to 5 above, wherein the amount of the solid inorganic    compound (B) is 1 to 20 parts by weight.-   7. An injection molded article comprising the aromatic polycarbonate    resin composition of any one of items 1 to 6 above.-   8. An extrusion molded article comprising the aromatic polycarbonate    resin composition of any one of items 1 to 6.

Hereinbelow, the present invention is described in detail.

First, explanations are given below with respect to component (A).

In the present invention, component (A) is a resin component mainlycomprising an aromatic polycarbonate.

In the present invention, the “resin component mainly comprising anaromatic polycarbonate” means a resin containing more than 50 parts byweight, relative to 100 parts by weight of the resin component, of anaromatic polycarbonate. Component (A) may contain only an aromaticpolycarbonate, or may further contain a thermoplastic resin other thanan aromatic polycarbonate.

As component (A), it is preferred to use an aromatic polycarbonate whichis obtained from an aromatic dihydroxy compound. Specific examples ofaromatic dihydroxy compounds include bis(hydroxyaryl)alkanes, such as1,1-bis(4-hydroxy-t-butylphenyl)propane and2,2-bis(4-hydroxyphenyl)propane; bis(hydroxyaryl)cycloalkanes, such as1,1-bis(4-hydroxyphenyl)cyclopentane and1,1-bis(4-hydroxyphenyl)cyclohexane; dihydroxyaryl ethers, such as4,4′-dihydroxydiphenyl ether and 4,4′-dihydroxy-3,3′-dimethylphenylether; dihydroxyaryl sulfides, such as 4,4′-dihydroxydiphenyl sulfideand 4,4′-dihydroxy-3,3′-dimethylphenyl sulfide; dihydroxyarylsulfoxides, such as 4,4′-dihydroxydiphenyl sulfoxide and4,4′-dihydroxy-3,3′-dimethylphenyl sulfoxide; and dihydroxyarylsulfones, such as 4,4′-dihydroxydiphenyl sulfone and4,4′-dihydroxy-3,3′-dimethylphenyl sulfone.

Among these aromatic dihydroxy compounds,2,2-bis(4-hydroxyphenyl)propane (the so-called “bisphenol A”) is mostpreferred. These aromatic dihydroxy compounds can be used individuallyor in combination.

In the present invention, aromatic polycarbonates which are preferablyused as component (A) can be produced by any conventional methods.Examples of conventional methods include an interfacial polymerizationprocess (e.g., phosgene process) in which an aromatic dihydroxy compoundand a carbonate precursor (e.g., phosgene) are reacted with each otherin the presence of an aqueous sodium hydroxide solution and methylenechloride as a solvent; a transesterification process (melt process) inwhich an aromatic dihydroxy compound and a carbonic diester (e.g., adiphenyl carbonate) are reacted with each other; a solid-phasepolymerization process in which a carbonate prepolymer obtained by thephosgene process or by the melt process is crystallized and subjected toa solid-phase polymerization (Unexamined Japanese Patent ApplicationLaid-Open Specification No. Hei 1-158033 (corresponding to U.S. Pat. No.4,948,871)); a method described in Unexamined Japanese PatentApplication Laid-Open Specification No. Hei 1-271426; and a methoddescribed in Unexamined Japanese Patent Application Laid-OpenSpecification No. Hei 3-68627 (corresponding to U.S. Pat. No.5,204,377)).

As an aromatic polycarbonate resin which is especially preferred ascomponent (A), there can be mentioned an aromatic polycarbonate resinproduced from a dihydric phenol (an aromatic dihydroxy compound) and acarbonic diester by a transesterification process. Such an aromaticpolycarbonate resin contains substantially no chlorine atoms.

The weight average molecular weight of the aromatic polycarbonate usedin the present invention is generally from 5,000 to 500,000, preferablyfrom 10,000 to 100,000, more preferably from 13,000 to 50,000, stillmore preferably from 15,000 to 30,000, still more preferably from 17,000to 25,000, most preferably 17,000 to 20,000.

In the present invention, the weight average molecular weight (Mw) ofthe aromatic polycarbonate can be measured by gel permeationchromatography (GPC) as follows. A calibration curve is obtained withrespect to standard monodisperse polystyrene samples using a polystyrenegel column and tetrahydrofuran as a solvent. The obtained calibrationcurve is modified by a calculation using the following formula:M_(PC)=0.3591M_(PS) ^(1.0388)

-   -   wherein M_(PC) represents the molecular weight of an aromatic        polycarbonate and M_(PS) represents the molecular weight of a        polystyrene, thereby obtaining a modified calibration curve for        a polycarbonate. The weight average molecular weight of a        polycarbonate is measured by GPC using the obtained modified        calibration curve.

Further, in the present invention, as component (A), two or more typesof polycarbonates having different molecular weights can be used incombination. For example, an aromatic polycarbonate usable as a rawmaterial for producing an optical disk, which in general has a weightaverage molecular weight (Mw) of from 14,000 to 16,000, can be used incombination with an aromatic polycarbonate usable as a raw material forproducing an injection-molded article or an extrusion-molded article,which in general has a weight average molecular weight (Mw) of from20,000 to 50,000.

Examples of thermoplastic resins (other than an aromatic polycarbonate)which can be preferably used in component (A) (which is comprised mainlyof any of the above-mentioned aromatic polycarbonates) include apolystyrene resin; a high impact polystyrene (HIPS) resin; anacrylonitrile/styrene copolymer resin (AS resin); a butylacrylate/acrylonitrile/styrene copolymer resin (such as BAAS resin andAAS resin); an acrylonitrile/butadiene/styrene copolymer resin (ABSresin); a methyl methacrylate/butadiene/styrene copolymer resin (MBSresin); polyester resins, such as a polyethylene terephthalate and apolybutylene terephthalate; a polyamide resin; a polymethyl methacrylateresin; a polyarylate resin; a core-shell elastomer used as an impactmodifier, and a silicone elastomer. Among these thermoplasticelastomers, from the viewpoint of improving the fluidity of the resincomposition, it is especially preferred to use an AS resin and/or a BAASresin. From the viewpoint of improving the impact resistance of theresin composition, it is preferred to use an ABS resin and/or an MBSresin. From the viewpoint of improving the chemical resistance of theresin composition, it is preferred to use a polyester resin.

With respect to the above-mentioned resin component (A) comprised mainlyof an aromatic polycarbonate, the amount of the thermoplastic resin(other than an aromatic polycarbonate) contained therein is preferablyfrom 0.1 to 30 parts by weight, more preferably from 0.5 to 20 parts byweight, still more preferably from 1 to 15 parts by weight, relative to100 parts by weight of the resin component (A).

Next, an explanation is given below with respect to component (B).

In the present invention, component (B) is a solid inorganic compound.

In the present invention, by virtue of the use of component (B), thearomatic polycarbonate resin composition not only has high flameretardancy, but also is improved with respect to stiffness and strength(due to the function of the component (B) as a reinforcing agent) andimproved with respect to dimensional precision (due to the function ofcomponent (B) as a filler).

In the present invention, component (B) may be in any of various forms,such as a fiber, a needle, a plate or a sphere, and is preferably in theform of a needle or a plate.

Examples of components (B) in the form of a fiber or a needle include aglass fiber, a carbon fiber, an aluminum borate whisker, a calciumtitanate whisker, a rock wool, a silicon nitride whisker, a boron fiber,a tetrapod-shaped zinc oxide whisker, and wollastonite.

Examples of components (B) in the form of a plate include talc, mica,pearl mica, glass flake and kaolin.

Examples of components (B) which are spherical (or substantiallyspherical) include glass beads, a glass balloon, carbon black, a glasspowder and silica (a natural silica and a synthesized silica).

In the present invention, as component (B), there can be mentioned acompound which has been surface-modified for improving the affinitythereof with the aromatic carbonate matrix of the resin composition ofthe present invention at an interface between component (B) and thearomatic carbonate matrix. The surface modification can be performed,for example, by a method in which a lipophilic organic compound isadsorbed onto the surface of component (B), or by a method in whichcomponent (B) is treated with a silane coupling agent or a titanatecoupling agent.

In the present invention, as component (B), it is preferred to use acarbon fiber or silicate compounds, such as talc, mica, pearl mica,wollastonite, kaolin, a glass fiber and a glass flake, moreadvantageously the above-mentioned silicate compounds.

Among the above-mentioned silicate compounds which can be preferablyused as component (B), it is especially preferred to use a silicatecompound containing a metal oxide and SiO₂. With respect to such asilicate compound containing a metal oxide and SiO₂, the silicate ioncontained therein may be present in any form. For example, each silicateion may be in the form of an orthosilicate, a disilicate, a ringsilicate, a chain silicate or a laminated silicate.

The above-mentioned silicate compound may be in the form of a compoundoxide, an oxyacid salt or a solid solution. The above-mentionedcomposite oxide may either be a mixture of 2 or more different oxides,or a mixture of an oxide and an oxyacid salt. The above-mentioned solidsolution may either be a solid solution comprising 2 or more differentmetal oxides, or a solid solution comprising 2 or more different oxyacidsalts.

The above-mentioned silicate compound may be a hydrate. With respect tosuch a hydrate, the water of crystallization contained therein may be inany form. For example, the water of crystallization may be in the formof a hydrogen silicate ion (i.e., in the form of an Si—OH), a hydroxideion (OH⁻) derived from a metal hydroxide, and a water molecule which ispresent in the voids of the hydrate.

As the above-mentioned silicate compound, either a natural compound or asynthesized compound may be used. As a synthesized compound, there canbe mentioned a silicate compound obtained by a conventional synthesismethod, such as a solid reaction method, a hydrothermal reaction methodor an ultrahigh-pressure reaction method.

In the present invention, as component (B), it is most preferred to usea silicate compound having a composition which is represented by thefollowing formula (1):xMO·ySiO₂·zH₂O  (1)

-   -   wherein each of x and y independently represents a natural        number, z represents an integer of 0 or more, and MO represents        a metal oxide component, wherein MO may contain a plurality of        different metal oxides.

Examples of metals M contained in the above-mentioned metal oxidecomponent MO include potassium, sodium, lithium, barium, calcium, zinc,manganese, iron, cobalt, magnesium, zirconium, aluminum and titanium.

With respect to the silicate compound represented by formula (1) above,it is preferred that the silicate compound contains CaO and/or MgO asthe metal oxide component MO. Further, it is more preferred that thesilicate compound contains substantially only CaO and/or MgO as themetal oxide component MO, and it is most preferred that the silicatecompound contains substantially only MgO as the oxide component MO.

Specific examples of silicate compounds which can be preferably used ascomponent (B) include talc, mica, wollastonite, xonotlite, kaolin clay,montmorillonite, bentonite, sepiolite, imogolite, sericite, lawsoniteand smectite.

As mentioned above, the silicate compound as component (B) may be usedin any form (e.g., a plate, a needle, a sphere and a fiber). However,the silicate compound is preferably in the form of a plate, a needle anda fiber, most preferably in the form of plate-shaped particles.

In the present invention, the term “plate-shaped particles” meansparticles in which the ratio (a)/(c) (wherein (a) is the averageparticle diameter of the particles as measured in terms of a mediandiameter of the particles wherein the median diameter is obtained by thebelow-mentioned method, and (c) is the average thickness of theparticles) is in the range of from 5 to 500, preferably from 10 to 300,more preferably from 20 to 200.

In the present invention, the above-mentioned average particle diameter(a) of component (B) is preferably in the range of from 0.001 to 500 μm,more preferably from 0.01 to 100 μm, still more preferably from 0.1 to50 μm, most preferably from 1 to 30 μm.

The above-mentioned average particle diameter (a) of component (B) ismeasured by either of the below-mentioned two methods, depending on theapproximate distribution range of the particle diameters of thecomponent (B).

When the particle diameters of component (B) are distributed in therange of from 0.001 to 0.1 μm, the average particle diameter (a) can bemeasured as follows. A photomicrograph of component (B) is taken using atransmission electron microscope, and the areas of 100 or more inorganiccompound particles on the photomicrograph are measured. From themeasured areas of the magnified particles, the actual areas (S) of theparticles are obtained by dividing the measured areas of the magnifiedparticles by the magnification of the microscope. From the thus obtainedactual areas S, the particle diameters of the inorganic compoundparticles are calculated by the formula (4S/π)^(0.5). From thecalculated diameters of the inorganic compound particles, the numberaverage particle diameter of the particles is calculated and defined asthe average particle diameter (a) of component (B).

When the particle diameters of component (B) are distributed in therange of from 0.1 to 300 μm, particle diameters of the inorganiccompound particles can be measured by a laser diffraction method (e.g.,a method using a laser diffraction particle size analyzer “SALD-2000”manufactured and sold by Shimadzu Corporation, Japan), and the mediandiameter of the measured particle diameters is calculated from themeasured particle diameters and defined as the average diameter (a).

In the present invention, the thickness (c) of component (B) in the formof plate-shaped particles is preferably from 0.01 to 100 μm, morepreferably from 0.03 to 10 μm, still more preferably from 0.05 to 5 μm,most preferably from 0.1 to 3 μm.

The thickness of component (B) in the form of plate-shaped particles canbe measured as follows. A photomicrograph of the component (B) is takenusing a transmission electron microscope, and the thicknesses of 10 ormore inorganic compound particles on the photomicrograph are measured.From the measured thicknesses of the magnified inorganic particles, theactual thicknesses of the inorganic particles are calculated by dividingthe measured thicknesses of the particles by the magnification of themicroscope. Then, an average value of the actual thicknesses iscalculated and the obtained average value is defined as thickness (c) ofplate-shaped particles as component (B).

Among the plate-shaped silicate compounds which are usable as component(B), most preferred are talc and mica.

A talc which is especially preferred as component (B) is a hydrousmagnesium silicate having a laminate structure, which is represented bythe following chemical formula: 4SiO₂·3MgO·H₂O. Such a hydrous magnesiumsilicate generally contains about 63% by weight of SiO₂, about 32% byweight of MgO, about 5% by weight of H₂O, and other metal oxides, suchas Fe₂O₃, CaO and Al₂O₃, and has a specific gravity of about 2.7.

Further examples of talcs which can be preferably used as component (B)include a calcined talc and a purified talc which has impurities removedtherefrom by washing with an acid, such as hydrochloric acid andsulfuric acid. Still further examples of talcs which can be preferablyused as component (B) include a talc having its surface renderedhydrophobic by a surface treatment with a silane coupling agent or atitanate coupling agent.

On the other hand, as a mica which is especially preferred as component(B), there can be mentioned crushed particles of a silicate mineralcontaining aluminum, potassium, magnesium, sodium, iron and the like.Specific examples of such micas include muscovite (chemical formula:K(AlSi₃O₁₀)(OH)₂Al₄(OH)₂(AlSi₃O₁₀)K), phlogopite (chemical formula:K(AlSi₃O₁₀)(OH)₂Mg₆(OH)₂—(AlSi₃O₁₀)K), biotite (chemical formula:K(AlSi₃O₁₀)(OH)₂(Mg,Fe)₆(OH)₂(AlSi₃O₁₀)K) and synthetic mica(fluorine-phlogopite; chemical formula: K(AlSi₃O₁₀)(OH)₂F₂Mg₆F₂(AlSi₃O₁₀)K). In the present invention, any of these micascan be used; however, muscovite is preferred.

Further, the above-mentioned mica may have its surface renderedhydrophobic by a surface treatment with a silane coupling agent or atitanate coupling agent.

In the present invention, the amount of component (B) is from 0.1 to 200parts by weight, preferably from 0.3 to 100 parts by weight, morepreferably from 0.5 to 50 parts by weight, still more preferably from0.8 to 30 parts by weight, most preferably from 1 to 20 parts by weight,relative to 100 parts by weight of component (A). When the amount ofcomponent (B) is more than 200 parts by weight, disadvantages are causedin that the melt stability of the aromatic polycarbonate resincomposition is markedly lowered and the mechanical properties of theresin composition having experienced the melting are inevitably lowered.On the other hand, when the amount of component (B) is less than 0.1part by weight, the flame retardancy of the resin composition islowered, thus rendering it impossible to achieve a high level of flameretardancy which is aimed at in the present invention.

When the aromatic polycarbonate resin composition of the presentinvention is used as a raw material for producing an injection-moldedarticle, from the view-point of obtaining an injection-molded articlewhich not only has excellent properties with respect to flameretardancy, melt stability, thermal aging resistance and resistance tomoist heat, but also has excellent weld strength and good appearance, itis especially preferred that the amount of component (B) is in the rangeof from 1 to 20 parts by weight, relative to 100 parts by weight ofcomponent (A).

Further, in the present invention, when a plate-shaped compound, such asa talc or mica, is used as component (B), the obtained aromaticpolycarbonate resin composition is advantageous not only in that, evenwhen the resin composition is in the form of a very thin shaped article,the resin composition has excellent flame retardancy, but also in thatthe resin composition is improved with respect to impact resistance,dimensional stability and electrical properties, such as insulatingproperties and tracking resistance (i.e., the resistance to theformation of a carbonized, electrically conductive path between twoelectrodes (having a potential difference) on the surface of aninsulating material). Therefore, in the present invention, it is mostpreferred to use talc or mica as component (B).

Next, an explanation is given below with respect to component (C).

In the present invention, component (C) is at least one compoundselected from the group consisting of an organic acid, an organic acidester, and an organic acid anhydride. In the present invention, by usingcomponent (C) in combination with the above-mentioned component (B),wherein component (C) is used in an amount wherein a mixture ofcomponent (B) and component (C) exhibits a pH value of from 4 to 8, ithas become possible to improve greatly the flame retardancy and meltstability of an aromatic polycarbonate resin composition.

Examples of organic acids which can be used as component (C) includeorganic compounds, each independently having at least one functionalgroup selected from the group consisting of an —SO₃H group, a —COOHgroup and a —POH group. Specific examples of such organic compoundsinclude organic sulfonic acids, organic carboxylic acids and organicphosphoric acids. Among these organic compounds, organic sulfonic acidsand organic carboxylic acids are preferred, and organic sulfonic acidsare most preferred.

The above-mentioned organic acid esters, and organic acid anhydrides,which can be used as component (C), are derivatives of theabove-mentioned organic acids. In the present invention, it is presumedthat, when any of the above-mentioned organic acid derivatives are usedas component (C), the component (C) is decomposed during the molding ofthe aromatic polycarbonate resin composition of the present invention,so that the component (C) functions as an acid. Therefore, for example,when a basic inorganic compound is used as component (B), component (C)neutralizes component (B). Thus, in the present invention, component (C)functions as a pH adjuster.

In the present invention, component (C) may be any of a monomer, anoligomer and a polymer.

Further, in the present invention, as component (C), two or more typesof compounds can be used in combination.

In the present invention, as component (C), it is especially preferredto use at least one compound selected from the group consisting of anorganic sulfonic acid, organic sulfonic acid derivatives (such as anorganic sulfonic acid ester) and an organic carboxylic acid.

When an organic sulfonic acid and/or an organic sulfonic acid esterare/is used as component (C), the aromatic polycarbonate resincomposition of the present invention exhibits an excellent meltstability, and the generation of volatile substances can be suppressed.Therefore, in such a case, the range of temperature employable for themolding of the resin composition becomes broad, and the final moldedarticle has an excellent appearance.

Examples of organic sulfonic acids which can be preferably used ascomponent (C) include aromatic sulfonic acids, such as benzenesulfonicacid, p-toluenesulfonic acid, xylenesulfonic acid, naphthalenesulfonicacid, diisopropylnaphthalenesulfonic acid, diisobutylnaphthalenesulfonicacid and dodecylbenzenesulfonic acid; and polymeric or oligomericorganic sulfonic acids, such as C₈–C₁₈ aliphatic sulfonic acids,sulfonated polystyrenes and methyl acrylate/sulfonated styrenecopolymer.

Examples of organic sulfonic acid esters which are usable as component(C) include methyl benzenesulfonate, ethyl benzenesulfonate, propylbenzenesulfonate, butyl benzenesulfonate, octyl benzenesulfonate, phenylbenzenesulfonate, methyl p-toluenesulfonate, ethyl p-toluenesulfonate,propyl p-toluenesulfonate, butyl p-toluenesulfonate, octylp-toluenesulfonate, phenyl p-toluenesulfonate, methylnaphthalenesulfonate, ethyl naphthalenesulfonate, propylnaphthalenesulfonate, butyl naphthalenesulfonate, 2-phenyl-2-propyldodecylbenzenesulfonate and 2-phenyl-2-butyl dodecylbenzenesulfonate.

Examples of organic sulfonic acid ammonium salts which are usable ascomponent (C) include decylammonium butylsulfonate, decylammoniumdecylsulfonate, dodecylammonium methylsulfonate, dodecylammoniumethylsulfonate, dodecylmethylammonium methylsulfonate,dodecyldimethylammonium tetradecylsulfonate, tetradecyldimethylammoniummethylsulfonate, tetramethylammonium hexylsulfonate,decyltrimethylammonium hexadecylsulfonate, tetrabutylammoniumdodecylbenzylsulfonate, tetraethylammonium dodecylbenzylsulfonate andtetramethylammonium dodecylbenzylsulfonate.

Further, preferred examples of organic sulfonic acids usable ascomponent (C) include those which have an —OH group, an —NH₂ group, a—COOH group, a halogen group or the like in addition to an —SO₃H group.Specific examples of such organic sulfonic acids include naphtholsulfonic acid, sulfamic acid, naphthylamine sulfonic acid, sulfobenzoicacid, organic sulfonic acids having a perchlorinated hydrocarbon groupor a partially chlorinated hydrocarbon group, and organic sulfonic acidshaving a perfluorinated hydrocarbon group or a partially fluorinatedhydrocarbon group.

As component (C), it is especially preferred to use aromatic sulfonicacids, such as benzenesulfonic acid, p-toluenesulfonic acid andnaphthalensulfonic acid.

In the present invention, the amount of component (C), based on theamount of component (B), is very important. When the amount of component(C) is too small or too large, it becomes impossible to achieve thedesired excellent effects of the present invention (i.e., it becomesimpossible to achieve simultaneously excellent flame retardancy,excellent melt stability, excellent thermal aging resistance andexcellent resistance to moist heat). Specifically, with respect to thearomatic polycarbonate resin composition of the present invention,component (C) is present in an amount wherein a mixture of component (B)and component (C) exhibits a pH value of from 4 to 8. The pH value ofthe above-mentioned mixture can be measured in accordance with JISK5101.

In JIS K5101, two types of pH measurement methods are prescribed,namely, the boiling method and the room temperature method. In thepresent invention, the measurement of the pH of the above-mentionedmixture is performed by the above-mentioned boiling method.

Further, in the measurement of the pH value of the above-mentionedmixture in which the pH is measured with respect to an aqueous solutionof the mixture of component (B) and component (C), when component (C)has a poor solubility in water and only an aqueous suspension isobtained by addition of the above-mentioned mixture to water, the pHvalue can be measured by a method in which the aqueous suspension isdispersed in an alcohol, and the pH value of the resultant dispersion ismeasured.

In the present invention, due to the above-mentioned requirement of thepH value of the mixture of components (B) and (C), an appropriate amountof component (C) varies depending on the type, shape and amount ofcomponent (B) used, and the type of component (C) used.

In the present invention, component (C) is preferably used in an amountwherein the mixture of component (B) and component (C) exhibits a pHvalue of from 4.2 to 7.8, more preferably from 4.3 to 7.6, still morepreferably from 4.4 to 7.4, most preferably from 4.5 to 7.2.

When component (C) is used in an amount wherein the mixture of component(B) and component (C) exhibits a pH value of less than 4 or more than 8,the resultant aromatic polycarbonate resin composition isdisadvantageous not only in that the desired excellent properties of theresin composition of the present invention cannot be achieved (i.e., allof the flame retardancy, melt stability, thermal aging resistance andresistance to moist heat of the resin composition are lowered), but alsoin that a shaped article produced from the resin composition sufferssilver streaks, so that the appearance of the shaped article becomesmarkedly poor.

Next, an explanation is given below with respect to component (D).

In the present invention, component (D) is at least one organic acidmetal salt selected from the group consisting of an organic acid alkalimetal salt and an organic acid alkaline earth metal salt. Component (D)promotes the decarboxylation of the above-mentioned resin component (A)during the combustion of the aromatic polycarbonate resin composition ofthe present invention, thereby improving the flame retardancy of theresin composition.

Preferred examples of organic acid metal salts which are usable ascomponent (D) include metal salts of organic sulfonic acids and metalsalts of sulfuric esters. These organic acid metal salts can be usedindividually or in combination.

Examples of alkali metals contained in component (D) include lithium,sodium, potassium, rubidium and cesium. On the other hand, examples ofalkaline earth metals contained in component (D) include beryllium,magnesium, calcium, strontium and barium. In the present invention,alkali metal(s) contained in component (D) is preferably lithium, sodiumand potassium, more preferably sodium and potassium.

Preferred examples of the above-mentioned metal salts of organicsulfonic acids include alkali/alkaline earth metal salts of aliphaticsulfonic acids and alkali/alkaline earth metal salts of aromaticsulfonic acids. In the present specification, the term “alkali/alkalineearth metal salts” is used to indicate both alkali metal salts andalkaline earth metal salts.

Preferred examples of alkali/alkaline earth metal salts of aliphaticsulfonic acids include alkali/alkaline earth metal salts of C₁–C₈ alkanesulfonic acids; alkali/alkaline earth metal salts of C₁–C₈ alkanesulfonic acids, wherein each alkyl group thereof is partiallyfluorinated; and alkali/alkaline earth metal salts of C₁–C₈perfluoroalkane sulfonic acids. Specific examples of thesealkali/alkaline earth metal salts of aliphatic sulfonic acids includesodium perfluoroethanesulfonate and potassium perfluorobutanesulfonate.

Examples of alkali/alkaline earth metal salts of aromatic sulfonic acidsinclude alkali/alkaline earth metal salts of aromatic sulfonic acidsselected from the group consisting of sulfonic acids of monomeric orpolymeric aromatic sulfides, sulfonic acids of aromatic carboxylic acidsor esters thereof, sulfonic acids of monomeric or polymeric aromaticethers, sulfonic acids of aromatic sulfonates, monomeric or polymericaromatic sulfonic acids, sulfonic acids of monomeric or polymericaromatic sulfones, sulfonic acids of aromatic ketones, heterocyclicsulfonic acids, sulfonic acids of aromatic sulfoxides, and condensationproducts of aromatic sulfonic acids in which the aromatic sulfonic acidmonomers are bonded through methylene linkages.

Preferred examples of alkali/alkaline earth metal salts of theabove-mentioned sulfonic acids of monomeric or polymeric aromaticsulfides include disodium diphenylsulfide-4,4′-disulfonate anddipotassium diphenylsulfide-4,4′-disulfonate.

Preferred examples of alkali/alkaline earth metal salts of theabove-mentioned sulfonic acids of aromatic carboxylic acids or estersthereof include disodium 5-sulfoisophthalate, sodium5-sulfoisophthalate, and polysodium polyethylene terephthalatepolysulfonate.

Preferred examples of alkali/alkaline earth metal salts of theabove-mentioned sulfonic acids of monomeric or polymeric aromatic ethersinclude calcium 1-methoxynaphthalene-4-sulfonate, disodium4-dodecylphenyletherdisulfonate, polysodiumpoly(2,6-dimethylphenyleneoxide)polysulfonate, polysodiumpoly(1,3-phenyleneoxide)polysulfonate, polysodiumpoly(1,4-phenyleneoxide)polysulfonate, polypotassiumpoly(2,6-diphenylphenyleneoxide)polysulfonate, and lithiumpoly(2-fluoro-6-butylphenyleneoxide)polysulfonate.

Preferred examples of alkali/alkaline earth metal salts of theabove-mentioned sulfonic acids of aromatic sulfonates include potassiumsalts of benzenesulfonate sulfonic acid.

Preferred examples of alkali/alkaline earth metal salts of theabove-mentioned monomeric or polymeric aromatic sulfonic acids includesodium benzenesulfonate, potassium benzenesulfonate, strontiumbenzenesulfonate, magnesium benzenesulfonate, dipotassiump-benzenedisulfonate, naphthalene-2,6-disulfonic acid di-potassium salt,biphenyl-3,3′-disulfonic acid calcium salt, sodium toluenesulfonate,potassium toluenesulfonate and potassium xylenesulfonate.

Preferred examples of alkali/alkaline earth metal salts of theabove-mentioned sulfonic acids of monomeric or polymeric aromaticsulfones include sodium di-phenylsulfone-3-sulfonate, potassiumdiphenylsulfone-3-sulfonate, dipotassiumdiphenylsulfone-3,3′-disulfonate and dipotassiumdiphenylsulfone-3,4′-disulfonate.

Preferred examples of alkali/alkaline earth metal salts of theabove-mentioned sulfonic acids of aromatic ketones include sodiumα,α,α-trifluoroacetophenone-4-sulfonate and dipotassiumbenzophenone-3,3′-disulfonate.

Preferred examples of alkali/alkaline earth metal salts of theabove-mentioned heterocyclic sulfonic acids include disodiumthiophene-2,5-disulfonate, dipotassium thiophene-2,5-disulfonate,calcium thiophene-2,5-disulfonate, and sodium benzothiophenesulfonate.

Preferred examples of alkali/alkaline earth metal salts of theabove-mentioned sulfonic acids of aromatic sulfoxides include potassiumdiphenylsulfoxide-4-sulfonate.

Preferred examples of the above-mentioned condensation products ofalkali/alkaline earth metal salts of aromatic sulfonic acids include acondensation product of sodium naphthalene sulfonate with formalin and acondensation product of sodium anthracenesulfonate with formalin.

On the other hand, preferred examples of alkali/alkaline earth metalsalts of sulfuric esters which are usable as component (D) includealkali/alkaline earth metal salts of sulfuric esters of monohydricalcohols and/or polyhydric alcohols. Specific examples of theabove-mentioned sulfuric esters of monohydric alcohols and/or polyhydricalcohols include methyl sulfate, ethyl sulfate, lauryl sulfate,hexadecyl sulfate, sulfuric esters of a polyoxyethylene alkyl phenylether, mono-, di-, tri- and tetrasulfuric esters of pentaerythritol,sulfuric esters of lauric acid monoglyceride, sulfuric esters ofpalmitinic acid monoglyceride, and sulfuric esters of stearic acidmonoglyceride. In the present invention, as component (D),alkali/alkaline earth metal salts of lauryl sulfate are especiallypreferred.

Further examples of alkali/alkaline earth metal salts usable ascomponent (D) (which are other than those mentioned above) includealkali/alkaline earth metal salts of aromatic sulfonamides, such assaccharin, N-(p-tolylsulfonyl)-p-toluenesulfoimide,N-(N′-benzylaminocarbonyl)sulfanilimide, and N-(phenylcarboxyl)sulfanilimide.

Among the above-mentioned alkali/alkaline earth metal salts which areusable as component (D), preferred are alkali/alkaline earth metal saltsof aromatic sulfonic acids and alkali/alkaline earth metal salts ofperfluoroalkane sulfonic acid.

In the present invention, the amount of component (D) is from 0.001 to 1part by weight, preferably from 0.005 to 0.8 part by weight, morepreferably from 0.01 to 0.7 part by weight, still more preferably from0.03 to 0.5 part by weight, still more preferably from 0.05 to 0.3 partby weight, most preferably from 0.06 to 0.2 part by weight, relative to100 parts by weight of component (A). When the amount of component (D)is more than 1 part by weight, the melt stability of the resincomposition is markedly lowered and the mechanical properties of theresin composition having experienced the melting inevitably becomelowered. On the other hand, when the amount of component (D) is lessthan 0.001 part by weight, the flame retardancy of the resin compositionis lowered, rendering it impossible to achieve an excellent flameretardancy, which is aimed at in the present invention.

Next, an explanation is given below with respect to component (E).

In the present invention, component (E) is a fluoropolymer which is usedfor preventing the dripping of flaming particles when the resincomposition is on fire. As component (E), it is preferred to use afluoropolymer having a fibril-forming ability. Specific examples of suchfluoropolymers include tetrafluoroethylene polymers, such as apolytetrafluroethylene and a tetrafluoroethylene/propylene copolymer.Among these, especially preferred is a polytetrafluoroethylene.

The above-mentioned fluoropolymers usable as component (E) may be in anyof various forms, such as a fine powder, an aqueous dispersion, and apowder mixture with another resin(s), such as acrylonitrile/styrenecopolymer (AS) and polymethyl methacrylate (PMMA).

Preferred examples of aqueous fluoropolymer dispersions which are usableas component (E) include Teflon™ 30J (manufactured and sold byDuPont-Mitsui Fluorochemicals Company Limited, Japan), Polyflon™ D-1,Polyflon™ D-2, Polyflon™ D-2C and Polyflon™ D-2CE (each of which ismanufactured and sold by Daikin Industries, Ltd., Japan).

As mentioned above, in the present invention, it is possible to use afluoropolymer in the form of a powder mixture with another resin(s)(e.g., AS resin and PMMA resin) as component (E). Such fluoropolymers inthe form of a powder mixture with another resin(s) are described in, forexample, Unexamined Japanese Patent Application Laid-Open SpecificationNos. Hei 9-95583 (corresponding to U.S. Pat. No. 5,804,654), Hei11-49912 (corresponding to U.S. Pat. No. 6,040,370), 2000-143966 and2000-297189. Specific examples of such powder mixtures include Blendex™449 (manufactured and sold by GE Speciality Chemicals, U.S.A.), andMetablen™ A-3800 (manufactured and sold by Mitsubishi Rayon Co., Ltd.,Japan).

In the present invention, the amount of component (E) is from 0.01 to 1part by weight, preferably from 0.05 to 0.8 part by weight, morepreferably from 0.08 to 0.6 part by weight, still more preferably from0.1 to 0.4 part by weight, relative to 100 parts by weight of theabove-mentioned resin component (A). When the amount of component (E)exceeds 1 part by weight, the mechanical properties of the resincomposition become disadvantageously poor. On the other hand, when theamount of component (E) is less than 0.01 part by weight, the flameretardancy of the resin composition is disadvantageously lowered, sothat the dripping of flaming particles occurs when the resin compositionis on fire.

In the present invention, if desired, any of various additives, such asa colorant, a lubricant, a mold release agent, a thermal stabilizer, anantioxidant, an ultraviolet absorber and an antistatic agent, may beadded to the aromatic polycarbonate resin composition.

The above-mentioned additives are generally used in an amount of 5 partsby weight or less, preferably 3 parts by weight or less, more preferably1 part by weight or less, relative to 100 parts by weight of thearomatic polycarbonate resin composition.

Hereinbelow, explanations are given with respect to the method forproducing the aromatic polycarbonate resin composition of the presentinvention.

The aromatic polycarbonate resin composition of the present inventioncan be produced by mixing the above-mentioned components (A) to (E), andoptionally other components, in their respective amounts as mentionedabove, followed by melt-kneading by means of a melt-kneader (e.g., anextruder). The mixing of the components can be performed by means of aconventional premixer, such as a tumbler and a ribbon blender. Further,the melt-kneading of the resultant mixture can be performed by means ofa conventional melt-kneader, such as a single-screw extruder, atwin-screw extruder and a co-kneader. As mentioned above, in the presentinvention, the components may be mixed together prior to feeding into amelt-kneader; however, it is also possible to feed each of thecomponents individually into a melt-kneader.

In the production of the aromatic polycarbonate resin composition of thepresent invention, there is no particular limitation with respect to theform of resin component (A), and resin component (A) may be in the formof, for example, pellets, a powder or a flake.

In the production of the aromatic polycarbonate resin composition of thepresent invention, it is preferred that, prior to feeding into amelt-kneader, component (B) is subjected to a chemical or physicaltreatment with component (C), to thereby bond component (C) to component(B) through a covalent bond, an ionic bond, an intermolecular force or ahydrogen bond.

The above-mentioned treatment of component (B) with component (C) can beperformed, for example, by the following method. A predetermined amountof component (C) is contacted with component (B) by spraying, dripping,wetting, immersion or the like. If desired, component (C) may be used ina molten form, liquid form or gas form. Then, component (B) andcomponent (C) are mixed together while stirring by means of a mechanicalmixing apparatus (e.g., a Henschel mixer, a Nauter mixer, a V-blender ora tumbler). After the mixing, excess amounts of components are removedfrom the resultant mixture by volatilization, and the resultant mixtureis dried. The above-mentioned mixing of components (B) and (C) whilestirring may be performed at a temperature not higher than the meltingpoint of component (C); however, it is more preferred to elevate thetemperature of the mixture to a temperature which is equal to or higherthan the melting point of component (C) so as to perform the mixing moreeffectively. The mixing time varies depending on the type of mixingapparatus used. However, the mixing time is generally from 1 minute to 3hours, preferably from 2 minutes to 1 hour, more preferably from 3minutes to 40 minutes, still more preferably from 5 minutes to 30minutes. With respect to the mixing apparatus, it is especiallypreferred to use a Henschel mixer or a Nauter mixer, each of which isequipped with a heater. In the above-mentioned method, it is preferredthat, after the mixing of components (B) and (C), an excess amount ofcomponent (C) is volatilized by pressure reduction and/or heating, andthat the resultant mixture is thoroughly dried.

The melt-kneader used for producing the aromatic polycarbonate resincomposition of the present invention is generally an extruder,preferably a twin-screw extruder. In the present invention, component(B) may be fed through a side feeder provided around a middle portion ofthe extruder. The melt-kneading is generally performed under conditionswherein the cylinder temperature is in the range of from 200 to 300° C.,preferably from 220 to 270° C., and the revolution rate of the extruderis from 100 to 700 rpm, preferably from 200 to 500 rpm; however, duringthe melt-kneading, care must be taken to prevent the generation of anexcess heat. Further, it is effective to provide an opening at adownstream portion of the extruder, so as to release the volatilizedsubstances therefrom. In such a case, the volatilized substances may bereleased from the opening under reduced pressure. Furthermore, ingeneral, the retention time of the resin composition in the extruder isgenerally in the range of from 10 to 60 seconds.

With respect to the method for producing a molded article from thearomatic polycarbonate resin composition of the present invention, thereis no particular limitation. Examples of molding methods includeinjection molding, gas-assisted injection molding, extrusion molding,compression molding, blow molding and rotational molding. Among thesemethods, injection molding and extrusion molding are preferred, andinjection molding is most preferred.

Examples of molded articles produced from the aromatic polycarbonateresin composition of the present invention include housings forcomputers (e.g., desktop computers and notebook computers), copyingmachines, printers, liquid crystal projectors, electric and electronicdevices, portable telephones, portable information terminals, batterypacks and household electric appliances; parts for frames of a liquidcrystal backlight; interior parts of a copying machine; electric andelectronic parts, such as resistors, terminals and deflection yokes fora television; parts for lighting apparatus; and flame retardant sheets(or insulating sheets) for electronic information devices.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinbelow, the present invention will be described in more detail withreference to the following Examples and Comparative Examples, whichshould not be construed as limiting the scope of the present invention.

In the following Examples and Comparative Examples, aromaticpolycarbonate resin compositions were produced using the followingcomponents (A), (B), (C), (D) and (E), and mold release agent.

1. Component (A): Aromatic Polycarbonate

The following substances (A-1) and (A-2) are used as component (A).

(A-1): A bisphenol A polycarbonate produced from bisphenol A anddiphenyl carbonate by melt transesterification, containing 300 ppm byweight of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate as ahindered phenol antioxidant, and having the following properties.

Weight average molecular weight (Mw)=21,800

Terminal phenolic hydroxyl group ratio (in terms of mole % of terminalphenolic hydroxyl groups, based on the total molar amount of allterminal groups)=35 mole %

The terminal phenolic hydroxyl group ratio was measured by nuclearmagnetic resonance (NMR) spectroscopy.

(A-2): A bisphenol A polycarbonate (trade name: Panlite AD5503; producedby phosgene process and sold by Teijin Chemicals Ltd., Japan), which hada weight average molecular weight (Mw) of 15,300.

2. Component (B): Solid Inorganic Compound

The following substances (B-1), (B-2), (B-3), (B-4) and (B-5) are usedas component (B).

(B-1): A talc having the following properties.

Average particle diameter=5 μm

Whiteness=96%

Apparent specific volume=2.3 ml/g

Specific surface area=8.5 m²/g

Water content=0.2%

Oil absorption=0.51 ml/100 g

pH=8.9

The average particle diameter of (B-1) was measured by means of aparticle size analyzer (trade name: SALD 2000; manufactured and sold byShimadzu Corporation, Japan). Specifically, using the above-mentionedapparatus, the particle diameters of (B-1) particles were measured by alaser diffraction method, and the median diameter was obtained from themeasured particle diameters and defined as the average particle diameterof (B-1).

The whiteness of (B-1) was measured in accordance with JIS P8123 usingdigital hunter ST (trade name; manufactured and sold by Toyo Seiki Co.,Ltd., Japan).

The specific surface area of (B-1) was measured by the BET adsorptionmethod using a specific surface area measuring apparatus (trade name:FlowSorb 2300; manufactured and sold by Shimadzu Corporation, Japan).

The water content of (B-1) was measured in accordance with JIS K5101using a water content measuring apparatus (trade name: STAC-5100;manufactured and sold by Shimadzu Corporation, Japan).

The oil absorption and apparent specific volume of (B-1) were measuredin accordance with JIS K5101.

The pH value of (B-1) was measured by the pH measuring method (boilingmethod) prescribed in JIS K5101.

(B-2): A mica (trade name: CLARITE MICA 200-D; manufactured and sold byKURARAY CO., LTD., Japan) having an average particle diameter of 90 μm,an average aspect ratio of 50 and an apparent specific gravity of 0.27g/cm³.

(B-3): A glass fiber (trade name: T-571; manufactured and sold by NipponElectric Glass Co., Ltd., Japan) having an average diameter of 13 μm anda fiber length of 3 mm.

(B-4): A glass flake (trade name: REF-160; manufactured and sold byNippon Sheet Glass Co., Ltd., Japan) having an average thickness of 5 μmand an average particle diameter of 160 μm.

(B-5): A hydrophobic fumed silica (trade name: Aerosil RY 200;manufactured and sold by Nippon Aerosil Co., Ltd., Japan) obtained bysubjecting a fumed silica (produced by the vapor phase method) having aprimary particle diameter of 12 nm to surface treatment with apolydimethylsiloxane.

3. Component (C): At Least One Compound Selected from the GroupConsisting of an Organic Acid, an Organic Acid Ester, and an OrganicAcid Anhydride

The following substances (C-1), (C-2), (C-3), (C-4) and (C-5) are usedas component (C).

(C-1): P-toluenesulfonic acid (guaranteed reagent, manufactured and soldby Wako Pure Chemical Industries, Ltd., Japan).

(C-2): Diphenylmethyl phosphate (DPMP) (guaranteed reagent, manufacturedand sold by Wako Pure Chemical Industries, Ltd., Japan).

(C-3): Methyl p-toluenesulfonate (guaranteed reagent, manufactured andsold by Wako Pure Chemical Industries, Ltd., Japan).

(C-4): Isophthalic acid (guaranteed reagent, manufactured and sold byWako Pure Chemical Industries, Ltd., Japan).

(C-5): Maleic anhydride (guaranteed reagent, manufactured and sold byWako Pure Chemical Industries, Ltd., Japan).

4. Component (D): At Least One Organic Acid Metal Salt Selected from theGroup Consisting of an Organic Acid Alkali Metal Salt and an OrganicAcid Alkaline Earth Metal Salt

The following substance (D-1) is used as component (D).

(D-1): Potassium perfluorobutanesulfonate (trade name: MEGAFACE F-114;manufactured and sold by DAINIPPON INK & CHEMICALS INC., Japan).

5. Component (E): Fluoropolymer

The following substance (E-1) is used as component (E).

(E-1): A powder mixture (trade name: Blendex 449; manufactured and soldby GE Speciality Chemicals Inc., U.S.A.) of a polytetrafluoroethylene(PTFE) and an acrylonitrile/styrene copolymer (AS), which mixture has aPTFE/AS weight ratio of 50/50.

6. Other Component

(Mold release agent): Pentaerythritol tetrastearate

(trade name: Unister H476; manufactured and sold by NOF Corporation,Japan).

EXAMPLES 1 TO 12 AND COMPARATIVE EXAMPLES 1 to 7

In each of Examples 1 to 12 and Comparative Examples 1 to 7, a flameretardant aromatic polycarbonate resin composition was produced bymelt-kneading components (A), (B), (C), (D) and (E), and a mold releaseagent, in their respective amounts (parts by weight) as indicated inTable 1, by means of a twin-screw extruder. Specifically, the productionof a flame retardant polycarbonate resin composition was performed asfollows.

In each of Examples 1 to 3, Examples 7 to 12 and Comparative Examples 1to 7, separately from the production of a polycarbonate resincomposition, components (B) and (C) were mixed together in a weightratio as indicated in Table 1, and the pH value of the resultant mixturewas measured in accordance with JIS K5101. The results are as shown inTable 1. On the other hand, in each of Examples 4, 5 and 6, the pH valueof a mixture of components (B) and (C), which was prepared during thecourse of the production of a polycarbonate resin composition, wasmeasured as described below.

In each of Examples 1 to 12 and Comparative Examples 1 to 7,melt-kneading of the raw materials (i.e., components (A), (B), (C), (D)and (E), and the mold release agent) was performed by means of atwin-screw extruder (trade name: ZSK-25; manufactured and sold by Werner& Pfleiderer GmbH, Germany) (L/D=37) under conditions wherein thecylinder temperature was 250° C., the screw revolution rate was 250 rpm,and the extrusion rate of the resultant resin composition was 15 kg/hr.

During the melt-kneading, the temperature of the molten resincomposition in the extruder was measured by means of a thermocouplewhich was provided at the die of the extruder. As a result, it was foundthat the molten resin temperature was in the range of from 260 to 270°C.

Further, during the melt-kneading, evaporation-removal of volatilesubstances was performed through a vent provided at a downstream potionof the extruder under reduced pressure, namely under a pressure of 0.005MPa.

With respect to the raw materials fed to the twin-screw extruder, ineach of Examples 1 to 3, Examples 7 to 12 and Comparative Examples 1 to7, components (A), (B), (C), (D) and (E), and the mold release agentwere preblended together for 10 minutes using a tumbler, and theresultant mixture was introduced into the extruder by means of a feeder.

On the other hand, in each of Examples 4, 5 and 6, only components (B)and (C) were preblended together in their respective amounts asindicated in Table 1 by means of a 10-liter Henschel mixer underconditions wherein the jacket temperature was adjusted to 200° C., thescrew revolution rate was 1,450 rpm, and the preblending time was 10minutes. The resultant mixture of components (B) and (C) was fed intothe twin-screw extruder together with the remainder of the raw materials(i.e., components (A), (D) and (E), and a mold release agent) to performmelt-kneading of the raw materials. The pH value of the above-mentionedmixture of components (B) and (C) was measured in accordance with JISK5101. The results are shown in Table 1.

By the above-mentioned melt-kneading of the raw materials, apolycarbonate resin composition was obtained in the form of pellets. Theobtained pellets were dried at 120° C. for 5 hours and molded by meansof an injection molding machine, thereby obtaining an injection-moldedarticle. Using the obtained injection-molded article, various propertiesof the resin composition were evaluated. Specifically, various testswere performed as follows.

(1) Flame Retardancy

The dried pellets were subjected to an injection molding using aninjection molding machine (trade name: Autoshot 100D; manufactured andsold by Fanuc LTD., Japan) at a cylinder temperature of 300° C. and amold temperature of 80° C., to thereby obtain two types of stripspecimens which have a thickness of 1.2 mm and a thickness of 0.75 mm,respectively. The strip specimens were maintained at 23° C. under ahumidity of 50% for two days. With respect to the resultant stripspecimens, the flame retardancy thereof was evaluated by the 50W (20 mm)Vertical Burning Test described in UL-94 standard. More specifically,the tests for “V-0”, “V-1” and “V-2” as prescribed in UL-94 standardwere performed (in the case where the evaluation by these tests wasimpossible, the flame retardancy of the specimen was evaluated as “NC”(non-classification)), wherein the level of the flame retardancy is asfollows: V-0>V-1>V-2).

Further, in each of Examples 3 to 10, a strip specimen having athickness of 1.0 mm was produced in the same manner as mentioned aboveand maintained under the same conditions as mentioned above. Withrespect to the resultant strip specimen, the flame retardancy thereofwas evaluated by the 500 W (125 mm) Vertical Burning Test (5VB)described in UL-94 standard.

(2) Flexural Modulus

The dried pellets were subjected to an injection molding using aninjection molding machine (trade name: Autoshot 50D; manufactured andsold by Fanuc LTD., Japan) at a cylinder temperature of 300° C. and amold temperature of 80° C., to thereby obtain a strip specimen having athickness of ⅛ inch. With respect to the obtained specimen, the flexuralmodulus (unit: MPa) thereof was measured in accordance with ASTM D790 at23° C.

(3) Melt Index (MI)

The melt index (MI) (unit: g/10 min) of the dried pellets was measuredin accordance with JIS K7210 at a furnace temperature of 300° C. under aload of 1.2 kg.

(4) Melt Index (MI) after Retention in the Molding Machine

The dried pellets of a resin composition were retained in an injectionmolding machine (trade name: Autoshot 50D; manufactured and sold byFanuc LTD., Japan) at a cylinder temperature of 300° C. for 20 minutes.Then, from the resultant resin composition in a molten form was produceda strip specimen having a thickness of ⅛ inch. With respect to theproduced strip specimen, the MI (unit: g/10 min) thereof was measured inaccordance with JIS K7210 at a furnace temperature of 300° C. under aload of 1.2 kg.

(5) Thermal Aging Resistance

The dried pellets of a resin composition were subjected to an injectionmolding using an injection molding machine (trade name: Autoshot 50D;manufactured and sold by Fanuc LTD., Japan) at a cylinder temperature of300° C. and a mold temperature of 80° C., to thereby obtain 5 dumbbellspecimens, each having a thickness of ⅛ inch. The obtained 5 specimenswere placed in a circulating hot air oven and maintained at 120° C. for2,000 hours. Then, the 5 specimens were subjected to a tensile test inaccordance with ASTM D638, and the thermal aging resistance wasevaluated according to the following criteria:

-   ◯: all of the 5 test specimens were broken after the tensile    strength thereof had reached the yield point;-   Δ: 1 to 4 test specimens were broken after the tensile strength    thereof had reached the yield point; and-   x: all of the 5 test specimens were broken before the tensile    strength thereof had reached the yield point.    (6) Resistance to Moist Heat

The dried pellets were subjected to an injection molding using aninjection molding machine (trade name: Autoshot 50D; manufactured andsold by Fanuc LTD., Japan) at a cylinder temperature of 300° C. and amold temperature of 80° C., to thereby obtain 5 dumbbell specimens, eachhaving a thickness of ⅛ inch. The obtained 5 specimens were maintainedat 80° C. under a relative humidity of 95% for 2,000 hours. Theresultant 5 specimens were subjected to a tensile test in accordancewith ASTM D638, and the resistance to moist heat was evaluated accordingto the following criteria:

-   ◯: all of the 5 test specimens were broken after the tensile    strength thereof had reached the yield point;-   Δ: 1 to 4 test specimens were broken after the tensile strength    thereof had reached the yield point; and-   x: all of the 5 test specimens were broken before the tensile    strength thereof had reached the yield point.    (7) Drop-Weight Impact Strength

The dried pellets were subjected to an injection molding using aninjection molding machine (trade name: Autoshot 100D; manufactured andsold by Fanuc LTD., Japan) under conditions wherein the cylindertemperature was 300° C. and the mold temperature was 80° C., to therebyobtain a plate-shaped specimen (150 mm×150 mm×2 mm (thickness)). Theobtained specimen was maintained at 23° C. under a humidity of 50% for 2days. With respect to the resultant test specimen, a drop-weight impacttest (falling dart impact test) was performed as follows. In thedrop-weight impact test, a falling weight (a falling dart) made ofstainless steel, which has a weight of 200 g and a spherical apex(diameter: ¾ inch (19 mm)), was used. The weight of the falling weightwas adjusted by attaching thereto a load-adjusting weight, and thefalling weight was allowed to fall from a height of 150 cm to the testspecimen. This falling operation was repeated several times whilevarying the weight of falling weight, to thereby measure the energyvalue (weight of the falling weight×falling height; unit: kgf·cm) atwhich the falling weight breaks and penetrates through the testspecimen.

Further, in the drop-weight impact test, with respect to a test specimenwhich was broken by the penetration of the falling weight, the state ofbreakage was observed to thereby evaluate the ductility and brittlenessof the specimen. When the falling weight did not penetrate through aspecimen, the state of breakage was evaluated as “no penetration”.

The results are shown in Tables 1 to 3.

EXAMPLES 13

The aromatic polycarbonate resin composition produced in Example 4 wasshaped into a sheet having a thickness of 0.7 mm by means of a 50 mmsingle-screw sheet extruder (trade name: PG50-32V; manufactured and soldby PLA GIKEN CO., LTD., Japan) (L/D=32) provided with a T-die and avent. The shaping was performed under conditions wherein the cylindertemperature was 290° C., the screw revolution rate was 50 rpm and theextrusion rate was 30 to 35 kg/hr.

The T-die had a slit width of 1 mm and a slit length of 300 mm.

The thickness of the sheet extruded through the T-die was adjusted bymeans of a roll having a temperature of 140° C., wherein the revolutionrate of the roll was adjusted within the range of from 2 to 4 m/min,taking into consideration the extrusion rate of the sheet, therebyobtaining a sheet having a thickness of 0.7 mm.

From the obtained sheet, 5 test specimens were cut out, each of whichhad a width of 12.7 mm and a length (in an extrusion direction of thesheet) of 127 mm. Then, the test specimens were subjected to a 20 mmVertical Burning Test in accordance with UL-94 standard. As a result, itwas found that the total burning time of the 5 test specimens was 32seconds, that no dripping of flaming particles was observed with respectto the 5 test specimens, and that, hence, the flame retardancy of theobtained sheet was “V-0”.

EXAMPLES 14 AND 15

In each of Examples 14 and 15, a polycarbonate flame retardant resincomposition was produced by performing the melt-kneading insubstantially the same manner as in Example 1, except that the ratio ofthe raw materials was changed to that indicated in Table 4.

The acryronitrile/styrene copolymer resin (AS resin) and themethylmetacrylate/butadiene/styrene copolymer resin (MBS resin) whichwere, respectively, used in Examples 14 and 15 are as follows.

(AS resin): An acrylonitrile/styrene copolymer resin containing 27% byweight of acrylonitrile monomer units and 73% by weight of styrenemonomer units and having a weight average molecular weight (Mw) of100,000.

(MBS resin): A metyl methacrylate/butadiene/styrene copolymer resin(KaneAce M-511, manufactured and sold by Kaneka Corporation, Japan).

The obtained pellets were dried at 120° C. for 5 hours, and the driedpellets were subjected to an injection molding by means of an injectionmolding machine, to thereby obtain injection-molded articles. Using theobtained injection-molded articles, various properties of the resincomposition were evaluated in the same manner as in Example 1.

The results are shown in Table 4.

TABLE 1 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6Example 7 Component (A) A-1 (parts by weight) 100 100 100 100 100 0 100A-2 (parts by weight) 0 0 0 0 0 100 0 Component (B) B-1 (parts byweight) 8 8 0 5 0.5 10 20 B-2 (parts by weight) 0 0 10 0 0 0 0 B-5(parts by weight) 0 0.3 0.3 0 0 0 0 Component (C) C-1 (parts by weight)0.1 0 0.03 0.2 0.02 0.4 0.5 C-2 (parts by weight) 0 0.1 0 0 0 0 0Component (D) D-1 (parts by weight) 0.01 0.01 0.1 0.1 0.1 0.1 0.15Component (E) E-1 (parts by weight) 0.2 0.2 0.6 0.8 0.8 0.8 1 Othercomponent Mold release agent 0 0 0 0.2 0.2 0.2 0.5 (parts by weight) pHvalue of the mixture of components 7.7 7.5 4.2 4.5 4.3 4.4 6.2 (B) and(C) Flame retardancy (sample thickness: 1.2 mm) V-0 V-1 V-0 V-0 V-0 V-0V-0 Flame retardancy (sample thickness: 0.75 mm) —¹⁾ —¹⁾ V-0 V-0 V-0 V-0V-0 Flame retardancy (sample thickness: 1.0 mm) —¹⁾ —¹⁾ 5VB 5VB 5VB 5VB5VB Flexural modulus (MPa) 3,150 3,120 3,200 2,900 2,400 3,450 3,700 MIvalue (g/10 min.) 16 17 18 19 25 27 10 MI value after the retention(g/10 min.) 18 25 22 21 26 29 12 Thermal aging resistance ∘ ∘ ∘ ∘ ∘ —¹⁾∘ Resistance to moist heat ∘ ∘ ∘ ∘ ∘ —¹⁾ ∘ Drop-weight Energy value (kgf· cm) >780²⁾ >780²⁾ >780²⁾ >780²⁾ >780²⁾ >780²⁾ >780²⁾ impact test Stateof breakage No pene- No penetra- No pene- No pene- No pene- No penetra-No pene- tration tion tration tration tration tion tration Notes: ¹⁾—means that the measurement was not performed. ²⁾>780 means that, evenwhen a load-adjusting weight having a weight of 5 kg was attached to thefalling weight (200 g) so that the impact load became 780 kgf · cm, thefalling weight did not penetrate through the test specimen.

TABLE 2 Example Example Example Example Example 8 9 10 11 12 ComponentA-1 (parts by 100 100 100 100 100 (A) weight) Component B-1 (parts by 1010 10 0 0 (B) weight) B-3 (parts by 0 0 0 5 0 weight) B-4 (parts by 0 00 0 5 weight) Component C-1 (parts by 0 0 0 0.02 0.02 (C) weight) C-3(parts by 0.2 0 0 0 0 weight) C-4 (parts by 0 0.1 0 0 0 weight) C-5(parts by 0 0 0.1 0 0 weight) Component D-1 (parts by 0.1 0.1 0.1 0.150.15 (D) weight) Component E-1 (parts by 0.6 0.6 0.6 0.8 0.8 (E) weight)pH value of the mixture of 5.2 6.5 4.2 4.5 4.3 Components (B) and (C)Flame retardancy V-0 V-0 V-0 V-0 V-0 (sample thickness: 1.2 mm) Flameretardancy V-0 V-0 V-0 —¹⁾ —¹⁾ (sample thickness: 0.75 mm) Flameretardancy 5VB 5VB 5VB —¹⁾ —¹⁾ (sample thickness: 1.0 mm) Flexuralmodulus (MPa) 3,200 3,150 3,200 3,000 2,700 MI value (g/10 min.) 14 1715 18 21 MI value after the retention 16 21 19 23 24 (g/10 min.) Thermalaging resistance ∘ ∘ ∘ ∘ ∘ Resistance to moist heat ∘ ∘ ∘ ∘ ∘Drop-weight Energy value >780²⁾ >780²⁾ >780²⁾ —¹⁾ —¹⁾ impact test (kgf ·cm) State of No No No breakage pene- pene- pene- —¹⁾ —¹⁾ tration trationtration Note: ¹⁾— means that the measurement was not performed. ²⁾>780means that, even when a load-adjusting weight having a weight of 5 kgwas attached to the falling weight (200 g) so that the impact loadbecame 780 kgf · cm, the falling weight did not penetrate through thetest specimen.

TABLE 3 Compara. Compara. Compara. Compara. Compara. Compara. Compara.Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Component (A) A-1 (parts byweight) 100 100 100 100 100 100 100 Component (B) B-1 (parts by weight)0 8 8 8 0 8 8 Component (C) C-1 (parts by weight) 0 0 0.1 0.1 0 0.1 0.4Component (D) D-1 (parts by weight) 0 0.01 0 0 0.01 0.01 0.01 Component(E) E-1 (parts by weight) 0 0.2 0.2 0 0.2 0 0.2 pH value of the mixtureof components (B) and —¹⁾ 8.9 7.7 7.7 —¹⁾ 7.7 2.5 (C) Flame retardancy(sample thickness: 1.2 mm) V-2 NC V-2 V-2 V-2 V-2 V-2 Flame retardancy(sample thickness: 0.75 mm) —¹⁾ —¹⁾ —¹⁾ —¹⁾ —¹⁾ —¹⁾ —¹⁾ Flame retardancy(sample thickness: 1.0 mm) —¹⁾ —¹⁾ —¹⁾ —¹⁾ —¹⁾ —¹⁾ —¹⁾ Flexural modulus(MPa) 2,400 3,100 3,100 3,100 2,400 31,000 31,000 MI value (g/10 min.)19 45 17 18 —¹⁾ —¹⁾ 27 MI value after the retention (g/10 min.) 21 —¹⁾19 19 —¹⁾ —¹⁾ 52 Thermal aging resistance ∘ x ∘ —¹⁾ —¹⁾ —¹⁾ —¹⁾Resistance to moist heat ∘ x ∘ —¹⁾ —¹⁾ —¹⁾ —¹⁾ Drop-weight Energy value(kgf · cm) >780²⁾ <150³⁾ >780²⁾ —¹⁾ —¹⁾ —¹⁾ <150³⁾ impact test State ofbreakage No pene- Brittle No pene- —¹⁾ —¹⁾ —¹⁾ Brittle tration fracturetration fracture Note: ¹⁾— means that the measurement was not performed.²⁾>780 means that, even when a load-adjusting weight having a weight of5 kg was attached to the falling weight (200 g) so that the impact loadbecame 780 kgf · cm, the falling weight did not penetrate through thetest specimen. ³⁾<150 means that, when a load-adjusting weight having aweight of 800 g was attached to the falling weight so that the impactload became 150 kgf · cm, the falling weight broke and penetratedthrough the test specimen.

TABLE 4 Example Example 14 15 Component (A) A-1 (parts by weight) 97 95AS (parts by weight) 3 0 MBS (parts by weight) 0 5 Component (B) B-1(parts by weight) 5 5 Component (C) C-1 (parts by weight) 0.2 0.2Component (D) D-1 (parts by weight) 0.15 0.15 Component (E) E-1 (partsby weight) 0.6 0.6 pH value of the mixture of 4.5 4.5 components (B) and(C) Flame retardancy V − 0 V − 0 (sample thickness: 1.2 mm) Flameretardancy —¹⁾ —¹⁾ (sample thickness: 0.75 mm) Flame retardancy —¹⁾ —¹⁾(sample thickness: 1.0 mm) Flexural modulus (MPa) 2,900 2,550 MI value(g/10 min.) 19 16 MI value after the retention 22 20 (g/10 min.) Thermalaging resistance —¹⁾ —¹⁾ Resistance to moist heat —¹⁾ —¹⁾ Drop-weightEnergy value (kgf · cm) >780²⁾ >780²⁾ impact test State of breakage Nopene- No pene- tration tration Note: ¹⁾— means that the measurement wasnot performed. ²⁾>780 means that, even when a load-adjusting weighthaving a weight of 5 kg was attached to the falling weight (200 g) sothat the impact load became 780 kgf · cm, the falling weight did notpenetrate through the test specimen.

INDUSTRIAL APPLICABILITY

The aromatic polycarbonate resin composition of the present invention isadvantageous not only in that it exhibits an excellent flame retardancy(even in the form of a thin shaped article) without using a brominecompound or a phosphorus compound as a flame retardant, but also in thatit exhibits excellent melt stability, so that the range of temperatureemployable for the molding of the resin composition becomes broad.Further, the aromatic polycarbonate resin composition of the presentinvention has excellent thermal aging resistance and resistance to moistheat, so that it can be advantageously used as a raw material forproducing various shaped articles (e.g., an injection-molded article andan extrusion-molded article).

1. An aromatic polycarbonate resin composition comprising: 100 parts byweight of a resin component (A) mainly comprising an aromaticpolycarbonate, 0.1 to 200 parts by weight of a solid inorganic compound(B), at least one compound (C) selected from the group consisting of anorganic acid, an organic sulfonic acid ester, and an organic monomericacid anhydride, 0.001 to 1 part by weight of at feast one organic acidmetal salt (D) selected from the group consisting of an organic acidalkali metal salt and an organic acid alkaline earth metal salt, and0.01 to 1 part by weight of a fluoropolymer (E), wherein said compound(C) is present in an amount wherein a mixture of said inorganic compound(B) and said compound (C) exhibits a pH value of from 4 to
 8. 2. Thearomatic polycarbonate resin composition according to claim 1, whereinsaid solid inorganic compound (B) is at least one silicate compoundselected from the group consisting of a plate-shaped silicate compound,a needle-shaped silicate compound and a fibrous silicate compound. 3.The aromatic polycarbonate resin composition according to claim 2,wherein said at least one silicate compound is selected from the groupconsisting of talc, mica, a glass flake and a glass fiber.
 4. Thearomatic polycarbonate resin composition according to claim 3, whereinsaid at least one silicate compound is selected from the groupconsisting of talc and mica.
 5. The aromatic polycarbonate resincomposition according to claim 1, wherein said compound (C) is selectedfrom the group consisting of an organic sulfonic acid, an organicsulfonic acid ester, and an organic carboxylic acid.
 6. The aromaticpolycarbonate resin composition according to claim 1, wherein the amountof said solid inorganic compound (B) is 1 to 20 parts by weight.
 7. Aninjection molded article comprising the aromatic polycarbonate resincomposition of any one of claims 1 to
 6. 8. An extrusion molded articlecomprising the aromatic polycarbonate resin composition of any one ofclaims 1 to
 6. 9. The aromatic polycarbonate resin composition accordingto claim 1, wherein the amount of said compound (C) is frpm 0.02 to 0.5part by weight.